Circuit arrangement for the selection of one of a number of individual devices



Apri 1965 J. L. DE KROES ETAL 3,1

NT FOR THE SELECTION OF ONE OF A NUMBER OF INDIVIDUAL DEVICES CIRCUIT ARRANGE-ME Filed April 6. 1960 2 Sheets-Sheet 1 INVENTOR JAN LOUIS DE KROES WILLEM H. J. NICOLAI AGE April 1965 J. DE KROES ETAL 3,177,409

CIRCUIT ARRANGEMENT FOR THE SELECTION OF ONE OF A NUMBER OF INDIVIDUAL DEVICES I Filed April 6, 1960 2 Sheets-Sheet 2 IE- ff].

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AGENT United States Patent 3,177,409 CIRCUIT ARRANGEMENT FDR THE SELECTIDN OF ONE OF A NUMBER OF INDIVIDUAL DEVICES Jan Louis de Kroes and Willem Hendrik Johannes Nicolai, Hilversum, Netherlands, assignors to North American Philips Company, Inc., New York, N.Y., a corporation of Delaware Filed Apr. 6, 1960, Ser. No. 20,285 Claims priority, application Netherlands, Apr. 7, 1959, 237,886 3 Claims. (Cl. 317-137) The invention relates to a lock circuit for the selection of one of a number of individual devices.

A lock circuit is a lock-out circuit which operates in such a manner that a group of individual devices waiting at a given instant for selection, must first be successfully selected before a later occurring group may be permitted to be selected. Such devices are used for the mutual locking of a number of individual devices, such that at any moment at least one of them can be in a definite control condition. This is the case, for example in a cross-bar system for automatic telephony, in which a number of registers co-operate with a common marking circuit and only one of the registers may be connected to the marking circuit. The object of a lock circuit is to make sure that each of the individual devices can come to its turn in due time, which need not be the case in all the lock-out circuits, because in some circuits certain devices may occupy a more favourable position than other devices and will consequently be selected preferably. It may occur that these other devices have to wait extremely long, because devices that have reported later come to turn sooner. In lock circuits on the contrary,

all the devices that have reported should first be finished before another device can come to turn.

Lock circuits are already known, which comprise an individual relay of each of the individual devices and a common lock relay. These circuits are constructed such that, under the control of the individual devices, the individual relays can be brought into an operating condition only when the lock relay is in a certain condition which in principle may be both the attracted and the non-attracted condition of the relay owing to the fact that the energizing circuit of the individual relays includes a contact of the lock relay. On attracting at least one of the individual relays, the energizing circuit of the lock relay is varied such that this relay passes over into the other condition, such that none of the other individual relays can be brought into the operating condition any longer. The lock relay maintains this condition as long as at least one of the individual relays is in the operating condition. As soon as the last individual relay reassumes the rest condition, the lock relay again reassumes the original condition, in which the individual relays can be energized again. The lock relay will then pass over into the other condition with a certain delay, in which all the individual relays to be considered for this purpose have had the opportunity to respond. In the known devices, selection of the individual devices takes place by means of a relay chain circuit of change-over contacts of the individual relays.

The invention provides a very suitable solution of the problem. In the circuit arrangement according to the invention, the individual relays are constructed as bistable polar relays which can be magnetized in one direction by the individual devices, while under the control of the individual relays which are in the operating condition, an additional counter-energization is supplied to all the individual relays.

In order that the invention may be readily carried into 3,177,4h9 Patented Apr. 6, 1965 effect, it will now be described in greater detail, by way of eXample, with reference to the accompanying drawings.

FIG. 1 shows a lock circuit comprising a number of bistable polar relays A, B, C, D, E, P, which are individually added to a number of devices RA, RB, RC, RD, RE, RF, which, for example, may be registers. The relays A, B, C, D, E, F are each provided with two Windings A1 and A2, B1 and B2 etc. and with a change-over contact a, b, 0 etc., the rest contacts of which are connected to each other in series in the energization circuit of the lock relay H. In the rest condition of the circuit, the lock relay is energized. The connected ends of the windings of the individual relays are connected to a pole of a source of supply (not shown) the other pole of which is grounded. If one or more of the individual devices, for example RB and RD, have to be selected, these devices close, in a manner which is not further described, their contacts cb and cd in series with the first windings Bi and D1 of the relays B and D, as a result of which these relays are energized and open their rest contacts b and d, so that relay H is released. Relay H closes via its rest contact 11, an energizing circuit via the second windings A2, B2 etc. of all the individual relays A, B, C etc. The windings A1 and A2, B1 and B2 of the various individual relays are wound such that the energizations of the two windings are neutralized. The original energization via the windings B1 and Di of the relays B and D will consequently be neutralized by the counterenergization via the windings B2 and D2, but these relays do not reassume the rest condition, since, as already stated, they are of the bistable polar type. The relays A, C, E and F on the other hand are not brought, in the operating condition by the energization via their second Windings A2, C2, B2 and F2 since the energization is operative in the direction of the rest condition. Should one of the contacts ca, cc, ce or cf be closed, the relays A, C, E or F still may not pass into the operating condition, since the closing of these contacts would result only in these relays receiving two neutralizing energizations. The conductor LE to the register RB is earthed via rest contact a and work contact [2, as a result of which for example a relay (not shown) of the register is energized to show that this register is selected and may be connected for example, to a common marking circuit. After the register has performed certain control operations it opens, via its contact cb, the energizing circuit of the winding B1, so that the relay B then reassumes the rest condition under the influence of the energization via the winding B2. As a result of this the register RD Will now be selected, owing to the fact that the conductor LD is connected to ground via the rest contacts a, b and c and work contacts d. As soon as the register RD has performed its task and contact cd opens, relay D, too, reassumes the rest condition under the influence of the energization of the winding D2, as a result of which the series circuit of rest contacts a, b, c, d, e and f is recovered again and attracts relay H. Via its rest contact h, relay H opens the counter-energizing circuit via the windings A2, B2 etc. Should in the meantime certain other registers, for example RA and RE, have reported for selection and consequently have closed their contacts ca and ce, this would not have any further influence, as already stated above, as long as relay H is released. On attracting relay H, however, the counterenergization via the windings A2 and E2 is removed, so that now the relays A and B will be brought into the operating condition under the influence of the energization via the windings A1 and E1. The relay H is a slowacting one, so that the relay H, on opening the rest contacts a and e, will be released only after a certain period which is suflicient to cause all the individual relays, the

(:9 first windings of which are energized, to pass over in the operating condition before the counter-energization is applied across contact it via the second windings.

FIG. 2 shows a variation which largely corresponds to the circuit arrangement as shown in FIG. 1. The counter-energization circuits across the second windings A2, B2 etc. of the individual relays A, B etc., however, are not connected by means of a lock relay, which is not present in this case, but are directly controlled by the individual relays themselves via the series arrangements of the rest contacts, a, b etc. In the rest condition of the circuit, the windings A2 F2 are short-circuited via this circuit. Now, if one or more of the contacts, ca, cb of the registers RA, RB etc. in series with the windings A1, B2 etc. are closed under the control of the registers, the corresponding relays pass over into the operating condition and open the short-circuits via the rest contacts a, b, etc. As a result of this, the windings A2, B2 etc. are energized via resistor R2. The direction of this energization is again opposite to that of the windings A1, B1 etc. The occurrence of the counterenergization is somewhat delayed, because the resistor R2 is shunted by the capacitor K which, on opening the rest contacts a, 1) etc., has first to be discharged. Then no other relays can pass over into the operating condition, as was also the case in the circuit shown in FIG. 1, because the energization across the first windings All, Bil etc. is removed by the counter-energization across the second windings A2, B2 etc. As soon as all the relays have again reassumed the rest condition, the windings A2, B2 etc. are short-circuited again via the circuit of rest contacts a, [1 etc. and, consequently, the counterenergization is removed. In order to prevent burning of the contact on closing this circuit as a result of too large a capacitor charge current, a comparatively small resistor R1 is connected in series to the capacitor which is shunted by the rectifier G which is polarized such that, on opening the circuit of rest contacts, it is conductive and offers a low resistance to the discharge current of the capacitor K. On closing the circuit of rest contacts, the capacitor K is charged, via the resistor R1, comparatively rapidly. The discharging again of the capacitor K via the resistor R2 proceeds comparatively slowly, so that the connecting of the counter-energization experiences such a delay that all the relays which are energized via the first winding at that moment, have the opportunity to respond.

The circuit arrangement may be varied in various ways without leaving the scope of the invention. In the circuits shown in FIGS. 1 and 2, the windings A2, B2 etc. are connected in parallel to each other, but, if necessary, they may also be connected in series. Instead of being produced via a second winding on the relays, the counterenergization for the various relays may also be obtained by superimposing a current of opposite sense in the energizing current via a single winding of the relays.

What is claimed is:

1. A lock-out circuit for the selection of a plurality of individual devices each having an indicating terminal and operating contacts, said lock-out circuit comprising a plurality of bistable polar relay means each having a first and second winding, and change-over contact means with a rest contact means responsive to energization of only aw too said second windings and work contact means responsive to energization of only said first windings, lock-out relay means having lock contact means, means energizing said lock-out relay means comprising a series circuit of said rest contact means, means simultaneously energizing said second windings comprising said lock contact means, means for energizing said first windings comprising means connecting each operating contact to a separate first winding, and means connecting each indicating terminal to the Work contact of the polar relay means to which the respective operating contact'is connected.

2. A lock-out circuit for selectively connecting a first terminal to a plurality of devices each having a second terminal and operating contacts, said circuit comprising a plurality of bistable polar relays with first and second windings, and first contacts with first and second contacting positions, said first and second positions being responsive to energization of only said first and second windings respectively, lock-out relay means having second contacts, means energizing said lock-out relay means comprising a series circuit of said first contacts in said second position connected between said first terminal and relay means, means comprising said second contacts for simultaneously energizing said second windings upon deenergization of said lock-out relay, means connecting each operating contact to energize a separate first winding, and means selectively connecting said first terminal to said second terminals comprising said first contacts in said first position.

3. A lock-out circuit for selectively connecting a first terminal to the second terminals of a plurality of devices having operating contacts, said lock-out circuit comprising a plurality of bistable polar relays having first and second windings and change-over contacts with rest and work positions, means connecting each operating contact to a separate first winding to establish the work position of the respective relay in the absence of energization of the respective second winding, means for simultaneously energizing said second windings to establish the rest position of the respective relays in the absence of energization of the respective first winding in response to change-over of at least one of said contacts to the work position, means connecting the second terminal of each device to the contacts of the relay to which the respective operating contact is connected, said relay contacts being connected in a chain to said first terminal whereby said first terminal may be connected to a second terminal by way of the contacts in work position of the respective relay and the contacts in rest position of at least one other relay, and only one second terminal may be connected to said first terminal at any time.

References Cited by the Examiner UNITED STATES PATENTS 1,900,095 3/33 Brownstein 317-1555 2,712,101 6/55 Salati 317---137 2,712,885 7/55 Winship 317-137 2,787,741 4/57 Bretschneider 3 17-15 5 .5 2,860,183 11/58 Lewen 317-437 SAMUEL BERNSTEIN, Primary Examiner. WALTER L. CARLSON, Examiner, 

1. A LOCK-OUT CIRCUIT FOR THE SELECTION OF A PLURALITY OF INDIVIDUAL DEVICES EACH HAVING AN INDICATING TERMINAL AND OPERATING CONTACTS, SAID LOCK-OUT CIRCUIT COMPRISING A PLURALITY OF BISTABLE POLAR RELAY MEANS EACH HAVING A FIRST AND SECOND WINDING, AND CHANGE-OVER CONTACT MEANS WITH A REST CONTACT MEANS RESPONSIVE TO ENERGIZATION OF ONLY SAID SECOND WINDINGS AND WORK CONTACT MEANS RESPONSIVE TO ENERGIZATION OF ONLY SAID FIRST WINDINGS, LOCK-OUT RELAY MEANS HAVING LOCK CONTACT MEANS, MEANS ENERGIZING SAID LOCK-OUT RELAY MEANS COMPRISING A SERIES CIRCUIT OF SAID REST CONTACT MEANS, MEANS SIMULTANEOUSLY ENERGIZING SAID SECOND WINDINGS COMPRISING SAID LOCK CONTACT MEANS, MEANS FOR ENERGIZING SAID FIRST WINDINGS COMPRISING MEANS 